The military may not like but they will follow orders. It is congress who they must convince. But of course you can't get much out of congress without the support of the American people and the American people tend to get their opinion about how the military should be regulated from the military people they know and disrespecting the uniform tends to piss most vets off so it is a bit of a circle. Using the uniform to promote your political views, even if they involve the military, would be considered disrespectful by most vets. If they were protesting cutting VA funding then maybe the vets would forgive them but not on much else.